/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/NiagaraParameterMapHistory.h
Does this parameter contain the "Previous" namespace as one of its intermediate namespaces?
namespace FNiagaraParameterUtilities { bool FNiagaraParameterUtilities::IsPreviousValue ( const [FNiagaraVariableBase](API\Plugins\Niagara\FNiagaraVariableBase) & InVar ) }